Throughout this specification, when discussing the application of this invention in relation to a surgeon using an endoscope, the term “distal” with respect to the ligation barrel, is intended to refer to a location that is situated away from the surgeon. The term “proximal” is intended to refer to a location that is near the surgeon and nearer to the surgeon than a point distal to the surgeon.
The treatment of tissue encompasses a variety of techniques such as electrocauterization, heat therapy, resection (removal of tissue), and sclerotherapy (the injection of medicine into target tissue). These treatment techniques usually involve the passing of medical instruments through the operating channel of the endoscope. The endoscope permits minimally invasive access as well as visualization and suction aids.
Another technique that frequently utilizes the operating channel of the endoscope is ligation, which involves applying a band or ligature around a vessel or portion of tissue, thereby cutting off blood or fluid flow and causing the tissue to necrose and separate from adjacent healthy tissue. Ligation is widely used to treat a number of medical tissue conditions, including, but not limited to, hemorrhoids, polyps, ballooning varices, and other types of lesions, including those that are cancerous. Typically, ligators are also used with a suction or vacuum means to draw the tissue into the distal tip, whereby the band is deployed over the base of the diseased tissue to cut off blood flow. The ligating device is typically activated by retracting a line (string, wire, or cable) that is attached to the ligator at the distal end of an endoscope and is threaded through the operating channel of the endoscope to the proximal end of the instrument. The ligator can be activated by mechanically pulling the activating line by means of a hand-operated reel or trigger, or a motor drive mechanism. Various other ligating devices use cooperating inner and outer members that slide the individual bands by pushing or pulling them from the tip of the inner or outer member, the bands being preloaded onto the inner or outer member prior to deployment.
To prevent having to withdraw the instrument from the patient, reload, and reintroduce it for treating additional tissue or vessels, devices have been developed that are capable of sequentially delivering multiple preloaded bands, thus shortening the procedure time and improving patient comfort. Multiple band ligating devices include designs that individually tether or otherwise secure the bands to the dispenser and then release them sequentially as needed, often by use of one or more strings extending to the proximal end.
It is often desirable to combine another endoscopic procedure with band ligation, such as sclerotherapy or tissue removal with a surgical snare. However, while the operating channel of the endoscope is often large enough to accommodate more than just an activating line from a ligator, combining the medical instruments necessary for the second procedure with the ligator can be problematic. Thus, there is a need for a ligating device that can be combined with other medical instruments in endoscopic procedures.
Band ligators are generally provided in multiple sizes to fit various scope diameters. The ligators sometimes have an internal ridge that acts as a positive stop to prevent the endoscopic cap from sliding proximally down the scope. This is made possible because the ridge has a smaller diameter than the diameter of the scope. The same ligator usually cannot be used on another endoscope having a different diameter. If the ligator is too big, when placed onto an endoscope of differing diameter, there is a risk that the tabs will obstruct the features usually found in the cap of an endoscope: the light source, working channel, and camera lens. A ligator that is too small will likely not fit securely over the cap of the endoscope. Thus, there is a need for a band ligator barrel that can accommodate endoscopes of varying diameters without obstructing the endoscope cap features.